Burr removing apparatus



July 16, 1946. ,1 w, KING ErAL BURR REMOVING' APPARATUS 5 Sheets-Sheet 1 I W m y Wu III... Ro/6 U E NQ HM mw N N .m .HHH .Illu m A R \m.\ VMN. ummm |..I||||, l 0 lI uuu w :l i 7 Q. illlwllm T QQ m Gf mmf.; o o o o A Q NW G W.. J .In ww vw m\ @www w mv u S I v I/ WS wm (1 0 NQ mg; NQ o o NT VM. H QQ mm Sk 1 J. w. KING Erm. A2,404,180

July 16, 1946.

' 4 4 BURR REMOVING ABPARATUS 4 5 lSheel:s-Sheev, 2

Filed May ll., '1945 Ill * 6. suHu-'AAUTH Y Arran/vtr July 16, 1946. J, vw.' KING ETAL l 2,404,180

' BURR REMOVING APPARATUS 'A Filed May ,11, 1945 sheets-sheet s Arron/ ver July 15,1946 J. w' KING Erm. 2,404,180

` 4 BURR REMOVING APPARATUS Filed May V11'l 1945 5 Iaaneen-smet 4 J WMA/6 6.570,61 FAU TH 19) A17 f 4.7#

Arron/Ey July 16, 1946. J. KING ET AL 2,404,180 "BURRI REMOVING 4APPAR-TUS Filed May l1., 1943 5 Sheets-Sheet 5 A wmf? Patented July 16,f 1946 UNITED STATE s PATENT oFElcE BURR REMovING APPARATUS Appliation Mayu, 1943, serial No.' '486.580

This invention relates to burr removing apparatus and more particularly to an apparatus for removing the burrs resulting from broaching surfaces of an article.

In the manufacture of some articles, itis desired to form cooperating surfaces thereof to conform very accurately to a desired contour and, accordingly, 'these surfaces are formed by broachs claims. (c1. zei-3:5)V

ing operations. When broaching is performed, it

quite frequently happens that burrs are thrown up by the broaching tool, which must be removed either by hand or by some machine designed for this purpose. Y

It is an object of the -present invention to provide a simple and inexpensive apparatus for removing burrs from articles. A' v- In accordance with one embodiment of the invention as applied to a telephone switching frame assembly which has had three of its surfaces surface-broached, mechanism is provided for simultaneously initiating the operation of clamping devices to clamp the frame in position andto initiate the operation of removing broaching burrs from edges vof each of the three surfaces, In the particular embodiment vof the invention chosen for illustration, the two side edges and an end edge of a surface, which has been formed to the desired dimension by a broaching operation, has the broaching burrs removed therefrom by cooperating cutting knives Aand files. The files which remove the burr from the end edges of the surfaces which have been broached are driven through a substantallycircular path-to finish the end edge to a high degreeof accuracy, whereas the two opposed knives are driven in a straight line tocut the two side edges of two of three broached surfaces simultaneously.

A better understanding of the invention may be had by reference to the following detaileddescription when considered in conjunction with the accompanying drawings, wherein Fig 1 is a View in perspective of a telephone crossbar switch vertical unit frame having three armature supporting legs which have been formed in a broaching operation, which legs are to be trimmed by means of the apparatus embodying the present invention;

Fig. 2 is a side elevational View, partly broken away, of an apparatus for broachingthe surfaces of the frame shown in Fig. 1 and showing some details of the mechanisms for driving the cutting knives;

Fig. 3 is a detail view of one of the cutting knives showing diagrammatically the path of travelthereof in performing its operation;

Fig. 4 is a planview ofthe 4apparatus shown in Fig. l, parts being broken away to conserve space and showing diagrammatically the actuating mechanisms for the clamps which hold the frame during the removalof the burrs therefrom;

Figs.,5, Gand 7 arefragmentary detail views of the cutting knives for removing the burrs from the side edges of portions of the .frame shown in Fig.v 1, Fig. 5 being a side elevational view of the knife and Figs. 6 and 7 comprising sectional views takenalong the lines 6-6 and 1- 1 of Fig. 5 in the direction of the arrows; i s

Figs. f8 and 9 are vertical sectionalviews on an enlarged scale taken substantially along therlines 8-8 ,andaf of Fig.4 inthe direction of the arrows and showingdetails of the clamping mechanismand the drivingmeansfor the files; Y

Fig 10 is a Vplan sectionjtaken, substantially along the line lO-V-ID of Fig. 8 in the direction o the arroWS;

Y ',Fig. 11 isa fragmentary front elevational Viewv of the clamping mechanism for holding a frame in positionVV in the apparatus and taken substantially along the line I I-.-IN I of either Fig. 8 or. Fig. 10; j., N.. i. Fig. 12 is a'plan sectional View taken substantially along theline V|2|`2 ofY Fig. 8 in the direction of the arrows showing .details of thedrive mechanism fortheknives .and theiiles; and

Fig. 13 is a vertical sectional view taken substantially along the line |3-I3 ofV Fig. 8 in the directionof the arrows.l Y Referringto the drawings, wherein like reference characters Vdesignate Ythe same parts throughout the several'views,particular reference being had to Fig. 1 wherein a telephone crossbar switch Vertical unit base assembly is shown .at I9, it will be seen that the base assembly comprises a mainframe member 20 having an armature .Supporting leg A2l* formed. integrally therewith. The 'main framemember 20 has an `inverted U-shaped member 422 suitablyattached thereto,y for ',example, by welding, and -this and 24. `The leg24 cooperates with theleg 2l to form the armature support of theswitch and the leg 2|,V leg 24 fand leg 23 arev all cut accurately by a broaching operation tor have their lower surfaces in the same plane. This results in throwingl up a burr valong the twoside edges and one end edge of the legs 23 and 24 `and also results in throwing up a burr at the front edge of the leg 12|, as viewed in Figgl. Since the legs 2|1`and 24 serve as pivotpoints for the `armaturejoi the switch andthe pivotrocks onnthe front' edge of Y also have the burrs removed from it.

The apparatus ifor removing the burrs from ed upon a suitable base and includes a Ydriving shaft V25 continuously driven bya motor 21 (Fig` jj 4),. The shaft 25 has a sprocket 'M rnounted`Yr thereon'f-or drivingY achain 29, which, in turn,`

engages a sprocket 55 of a single revolution-clutch f 62 mounted on the lever r52 engaging the high Y the legsof. the switch frame assemblyl ismount-V SI vof any suitable type, which may-bejendered operative to drive ashaft32 throughya single 1 revolution each Vtime al controlling handle 33 is .Y depressed', The details of construction., of: theY single V`revolution clutch 3 I, Ynot forming" an" es: 1 sential portion of thepre'sent invention; havel. l .I not been shown in detail and it will be understood I that any suitable single revolution-clutch operable as described may bel used in the apparatus. In additonto driving the shaft-32 through one cycle of rotation, the single revolution clutch 3l, when rendered operative by manipulating the handle 33, also drives a cam A3.4 through a single revolue tionto operate a switch 35 for supplying power to'ner'gize either a coil 361er a coil 31 forming. a part ofA a solenoid operated switchhavinga shiftablefcore 38 which will be attracted by either the core Segorl, depending upon which of the coils t.

Vclamping,pins 51 and 5,3 will clampthejmain 35, whenthe apparatusis in its normal inoperative'position, normallysupplies current tothe coil 31 and. fluidlunder pressure will be directed Vfrom afsurce Knot Shown) through' a pipe 4l,

through the passages in the valve, to the fr on-t end of a cylinder 42. clutch..3| becomes operative due to theoperation of the handle V31%,.the switch 35. will disconnect However, assoon as the power fromithe. 'coil r31 and connect power to Y operate thecoil' 35,:thereby movingsthevalve l5 to theopposite positionto that shownto direct the fluid underV pressure from theV pipe Mfto the of -a set screw 54, and serves to rock the sli-aft 53 each r.time the link 5l is actuated. The shaft 53 is journalled in an irregularlyshaped standard and carries alever 'atits right end, as seen most clearly in Figs. 11 and 12. At their upperV ends, the levers 52 and 55 carry clamping pins 51 and 58, whichare VslidableV in vshouldered'apertures .59fand 55 (Figs.8 Vand 9) [and are urged towardthe frame Vassemblyfl@ to clamp it when f thefshaftl5`3 isrockedlcounterclockwise, as viewed Y in Fig. 8 orfclockwise, as viewedinlig. 9, Vas will begdescribedr more in detail hereinafter. The

` lever?5lhasfaljstud'shaft 5I .xed init which `carries afreely rotatable cam roller 62 (Figs.` 8

Vand-13) .i Y The cam roller VV62V engages a cam sur; `face 63 formedV onalever 64,- which is,-in turn, mounted upon-a pivot. stud 65 attached Vto "an 4 of clamping position when the lever 52 is rocked clockwise, as shown in Fig. 8, due to the cam roller portion of the cam surface 63 on the lever 5e.

When a frame assembly l9'is to be operated upon, it may'beplaced; as shown rnost clearly in Figs. l0 and-11, withthe lower edgerof the main frame member 2U resting on a support block Q15, whichvhas a cut-out 16 formed in it for re- Iceiving a depending portion of the main frame- Y lwork 20. besupported upon a support block 11; which fits finto/the Ulshaped member 22. The lever 674Y will The leftend (Figs. 10J 11 and 13) will clarnpjthe-legj, of the U-shaped member 22 against thesi'de',V of the support Yblock 'l1V and the -frame'member 2!V against the front face of the support block 11 andan upwardlyY extending frame member 18 formed integrally with the sup- V2d Y port block 15. The support block 11 is also provided withan upwardly' extending frame' member19,l against 'the front surface Vof which the U-shaped member 22 will bear. The two frame members 18 and 19 are attached to legs 8l! and 8|, respectively, of kaA substantiallyl U-shaped bracket82; which is, in turn, mounted upon `an upwardly extending portion 8.3 of theV 'standard Injaddition' to being supported by Ythe U- shaped memberA 82, at their upper ends, theV sup'- port blocks 1,5 and11 rest upon and arefixed to the portion ofthe standard 55 in'which the rocker shaft 53 is journalled, as may be seen particularly by reference to Figs. 8 and 9. In yaddition to the clampingjmechanisms just described, the lever 52 is providedwith a rearwardly extending clamping projection 84, which, when the lever is moved to its operative position, as shown in Fig. 8, will engage theupper surface of' the` U-shapedmember 22 to clamp it tightly in place-on the upper surface'of the support block 1p1, thus torhold the frame kassembly Yl during the succeeding operations'thereon. Y l Y' 4'By means ofV the clamping mechanism just described, aA switch 'frame assemblyV I9 to haver the burrs removedzfrom it may be clamped in posi? tion'tobe worked upon by files 90, Hand 92 and cuttingknife assemblies 93 andllf. The shaft Shin its cycle of rotation, will operate' theA files SU, Sl .and 9.2 Vand thej cutting knife assemblies $3 andimd in a xedsequence starting Y from Athe Vnorrn inoperative; position of the apparatus as shown' in Fig. 2 .1 The first/operation performedA on the frame E e iseffected byv the cutting knives, as shown most clearly` in Figs. 5, V6 and 7, where theputtingiknife assemblyi'isshown, In this assembly, a' pairmof, irregularly Yshaped knife blades 55 and arefrnountedupon a block 91. The blockl, asishownjjniost clearly in Fig. 11, is'rroyidedm into a 'short'.rockshaft Selby means of rivets Ill!) the block 91, may roclfgftoA a-jlimitedextent in a slot' VUlli formfedin a siiloportY block 102,'which extending portion 66 of thestandard55.,"I1`he lerici- 63 is normally urged torock counter-clockwiselFigs. 11 and 13) by a compression spring F51.V

of the iframe assembly I9 and hold it inposi'- fr' tion to be worked upon, but will be cammed out l serves'as a bearing .for supporting the rock shaft f 9S .The"cutting knife assemblyjSAis similar in positioned tomthe'rlght (Figs. 5 arid '7) V(lf-.afgllide f i laV dependir'ifgi'portionu 98 riveted cable lever I I projection |01. Similarly, the knife blade 951s and |09 will engage opposite sides of the leg-24 and will guide the knife blades 95 and 96 into vengagement with the burrs formed in thel previous broaching operation. Since the blades 95 and 96 may not be moved with respectI to each other, but move as a unit, the guide projections |01 and |09 will guide the knife blades 95 and 96 into engagement with the edges of the leg 24 as the cutting knife assembly 93 is moved from I left to right, as viewed in Fig. 5.V TheV two knife blades 95 and 96 are held on the block 91 by means of a machine screw Y| I and the supporting block |02`is fixed on the right end (Fig. 2) of a recipro- The rock shafts 99 and |03 are held in place in theblock |02 by backing plates ||2 and I I3 (Figs. 2 and 11) suitably attached to the block |02 which is, in turn, fixed to the leverv I by means of a pair of machine screws l|4.

The reciprocable lever is slidable in an oscillatable housing |2|, which is pivoted on an upright |22-||22, in turn mounted upon the base 25. The upward movement of the oscillatable housing |2| is limited by an abutment screw |23 threaded into a cross head |24 extending to the right (Fig. 4) of a standard |25, which is, in turn, suitably mounted on the lbase 25. The undersurface of the oscillatable housing |2| hasa stud |26 set into it for retaining compression spring |21 in lposition to bear against the underside of the housing and'urge the housing upwardly. A guide stud |26 extending from the base of the standard |25 serves to position the bottom end of the compression spring |21 and also cooperates with the stud |26 and abutment to prevent the housing |2| from oscillating beyond a predetermined point. Extending upwardly fromthe base plate 25 is a bifurcated guide standard |29, which engages the two side edges of the lever||| to guide the front end thereof. An L-shaped lever |30, pivotally mounted on a pin |3|, which is, in turn, mounted on a bracket |32, is normally urged to the position shown in Fig. 2` by a contractile spring |33 attached to the lever |30 and to the guide standard |29. The amount of movement of the lever |30 in a-counter-clockwise direction about its pivot pin |3| is limited by an abutment screw |34, which strikes the base 25. The upper end of the lever |30 lserves as a camming 'surface for engaging the undersurface of the lever as seen most clearly in Fig, 2L, to prevent the lever from moving downwardly during a cutting operation of the knife blades v95 and 96 when the lever is moved to the left, whereby the cutting knife assemblies 93 and 94`wi11 trave1 in a straight une, as indicated by the line |35 (Fig. 3). The lever |.|is provided with a cam slot |36 (Fig. 3) for receiving a camming pin |31, which moves through a circular path to actuate the lever As seen in Fig. 2, the camming pin |31 rotates counter-clockwise, being mounted upon a primary lever |38, which is, in turn, iixed to the shaft 32 by means of a set screw |39. The primary lever |38 being driven by the shaft 32 will carry the camming pin |31 through a circular path'. In the first portion of its travel from the position shown in Fig. 2- in a counter-clockwise direction, the pin |31 will engage the left side of the cam slot |36 to slide the lever to the left. Since the spring-|21 holds the housing |2| up against the abutments'crew 6 |23, the lever will travel in a straight line, as indicated by the course of the knife blade 96 in Fig. 3 at the line |35. However, as soon as the camming pin |31, in its circular path of travel, v

has passed beyond a horizontal position a short distance and after the cutting knife assemblies 93 and 94'have moved across the legs 23 and 24 of the frame assembly I9, the camming pin V|31 will engage the bottom edge of the cam slot V|3|; and thelever and housing |2| will bevrocked clockwise about the pivot mounting for the housing |2| and the 'cutting knife assemblies 93 and 94 will then follow the path designated |40 (Fig. 3) for-the knife blade 96. When the lever is thus moved through the circular path, as indicated by the line |40, the forward end thereof will strike the left Side (Fig. 2) of the lever |30 to rock it about its pivot pin |3| in a clockwise d-` rection untilthe spring |21 forces the lower surface of the cam slot tightly against the camming pin |31 toward the end of its travel backto the position shown in Fig. 2, at which time the lever |30 will slip 01T the right end of the lever and return to the position shown.

The shaft 32, as seen most clearly in Fig. 12, is journalled in a bearing forming a part of the standard 55and, in addition to the lever |38 mounted at its left end (Fig. 12), has a lever |46 mounted at its right end. Each of the levers |38.and |46 is forked, as shown at |41 and |48,

respectively, for receiving levers |49 and |50,

which .are pivoted on the levers |38 and |46 by means of pins |5| and I 52. The levers |49 and |50 are urged to rock with respect to the levers |38 and |46 in a direction toward the shaft 32 by springs |53 and |54, which are attached to the levers |49rand |50 `intermediate their ends and are attached to brackets |55 and |56, respectively, which are, in turn, mounted by means of machine screws |51|51 on flattened surfaces of the levers |38 and |46. the levers |49 and |50 have stud shafts |58 and |59, respectively, mounted in them, which carry Vcam rollers and |6I, respectively, in engagement with stationary cams 62 and |63 fixed to |49. Similarly, the stud shaft |59 pivotally supports a lever |68, which is urged to rotate clockwise with respect to the shaft |59 (Fig. 9) by a contractile spring |69. The levers |64, |65 and |68 are all of exactly the same construction and are each'provided with a projecting portion |10, to which their respective springs are attached, and which Vengage pins |1| on their respective levers |49 and |50 to prevent movementk of the levers |64, |65 and |61 .beyond the position shown in Figs. 8 and 9. Each of the levers |64, |65 and |68 have a notch |14 formed in them at their free ends, as shown in Fig. 9, for 1eceivingthe files 90, 9| and 92, which are clamped in place in the notch |14 by a clamping plug |16 attached to each of the levers adjacent their hubs. Y

The cams |62 and |63, as will'be apparent from Figs. 8 and 9, areof similar construction; the cam |63 being slightly larger than cam |62 since its associated cam roller |6| must direct the file 92 through a slightly different path than that through .which the cam roller |60 guides the iiles and9l. i 1 f At their free ends..

Yapparatus by dropping it into position Wherethe base/'of the U-shaped frame 22 will engage the upper surfaceof the block 'l1l and where the lower edge of the frame 201wil1`engage the 'upper sur,- face of the support rblock 15." The assembly.V i9

'may' be placed inthis position with the rear ledge Vofit engaging the face of the -fr'amernembers Y 18 and 19 or may be dropped into `position where the frame 20 `will rest against theclampmgpms 51 and 58 and the handle 33 maythen be manip ulated to cause the single revolution clutch 3| to interconnect the shaft s2 Ywith the seance. As

Y the shaft 32 starts to rotate, the switch 35 be operated to supplyr current'to the coil 36, ats tracting thefsolenoid coil V38k and reversing valve 40 from the fpositionshown. WhenY the Y valve 46 is reversed, fluid under pressure will be `directed through the pipe lll through the valve E to the upper or rear end (FlgA) of theeylinder 42. When uid under pressureis supplied to the rear end of the cylinder 42, the pistonA rod B will be moved downwardly, as viewed in Fig. 4, or to the right, as viewed 1n Figs. 2 and 8, therebyfto rock the f u counter-clockwise. As the lever 52 rocks counter-clockwise, the lever 55 will rock clockwise,

shown inrFig. 9, and the clamping pinsv51 and 581will thereupon clamp the frame assembly i9 against the front surfaces of the frame members 18 and 1Q. When the lever V52'reaches the end'Y of its travel to clamping position, the clamping projection 84 will Vengage the'upper surface Vof the U-shaped member 22 to clamp it against the upper surface of the support blockrl'lV and while the lever 52 is moving to the position 'shown inl FigLS, the cam roller 62 will roll downY the face of 'the cam surfaceY 63 on clamping lever '55, thereby shifting theY frame assembly |29 vto a proper position Ywhere the inner surface of theV lever 52 and .rock` shaft 53 pinV |31' ceasespto efect' a downward thruston Vthe lever 'atavhich time the spring |21`will start gto push the-'lever backup to the position shownin Fig. 2.' v ,i

Duringthe second half cycle ofthe shaft 32, the 'filing portion ofjthe apparatus will become effective tofile the breaching` burrs off the legsV 2l, 23"and-2', at YWhich=ti1r1e .the files 99, 9| and 92 will, start from theV position'shown in Figs. 8 and 9, which'is the vposition they occupy in approximately the last quarter of cycle of rotation of the shaft 32. The fileswill be urged to retain the angular position shownrin' Figs. Sand 9 as they travel upwardlyybutiof course,.theywill be rocked about the stud'shafts |58 and |59 due to their engagement With.V the legs 2| 23 and 24,

Y and they;willfthus very "slightly round olf the leg 23 will bearagainst the right hand side (Fig. i

13) of the support blockll just prior to theV final clamping ofthe assembly I9 by the clamping projection 8. This operation of clamping the assembly in position to be worked upon willY occur in the very first portion of the cycle of rotation of the shaft 32 and as soonas the'part is clamped in place, the cuttingV knife assembles 93 and 94 will become effective due to the movement of the reciprocable lever to the leftiun-Y der the action of the camming pin |31.Y nAs described hereinbefore, the cutting knifevassem'- blies 93 and 94 will folloWthe path indicatedby curved and straight lines 'l Vand 435 1(Eig: :3) te, in the first half cycle of the shaft 32, cutoff any burrs formed along the side edges of thelegs 23 and 24.' In performing this operation, the lever will be prevented from tilting clownA wardly due to the engagement of the undersur facethereofV withY the .top surface of the lever t 13B' and, therefore, the Y leverVV I| will travelY straight toward the rear of the machine yinY a sub` V stantially horizontal path; As soon as the cutting 'knife assemblies have clearedV the legs 2l, 23 and 24, the lever |.I Land the knife Vassemblies willltravel through an arc, as indicated bythe *Y Yline |40, the lower right end (Fig. 2) 'of thel'ever 'Y Y| |Y` having passed of'theupper surface lofithe clampingfmeans for holding an article, a knife f Y lever I 30, will lthenY engage' the lever |36 'and rock it clockwise about the'pin |3| until Vthe Ycarnrm'ng corners ofthe leg'sjand remove v any burrs which might have been.v formed thereon. As soon as theistud shafts|58 and |59 beingguided'by their respective cam'rollers IBELand'IGI reach the top ofthe1vertical VportionV of the cams |62 and'|63, l

they will start to move away from the frame assemblyV I9 clamped in the apparatus andas the shaft 32 completes its cycle of operation, will assume the angular'positicn shown in Fig. 2.

What is claimed is: I

l. `A burr removing apparatus comprising a clamping means for holding an article, a knife for cutting burrs from one Vporti'onof the article, a `il'e for filing burrs from another portion of the article, a cam and vcrank shaft rotatable through a single cycle to cause operation of the clamping means, the knife and the file, means on the cam and crank shaft for imparting movement to the knife, and meanscooperating with the means onk the cam andicrank shaft to guide the knife inra rectilinear path Vandin an arcuate path.

V2. A burr f removingV apparatus comprising a clamping means' forV holding anarticle, a knife for cutting burrs from lone portionrof therarticle,

aille foriiling'burrs from another portion ofl the article, a ca m and Vcrank shaft rotatable 1 through a single cycle to Ycause operation of the clamping means, the -knife and `the rile, means on the cam and crank shaft foi/carryingV thefiles through a rotary path, and a stationary cam surrounding theshaftfor guiding the file.

3. A burr `removing apparatus comprising a clampingr means for'holding an article, a knife for cutting burrs from one portion of the article, Va flefor'filingy burrsfrom another portion of the article, a cam andv crank Vshaft rotatable through asingle cycle to cause operation of the clamping means,rthe knife and the file, means on the cam and crank shaft for carrying the les through a rotaryv path, a stationary cam surrounding'the shaft for guiding the le, and means tending to hold thefle at a predetermined angle to the article.'

`4. KVAY burr removing apparatus comprising a for cutting burrs from one portion of the article, a lefor filing burrs from another portion of the article,a camand crank shaft rotatable through Y a singlecycle to` cause operation of the clamping Y means, the knife andthe laand meansA mounted on thercarn and crank shaft for resiliently sup,`

with respect to thejcain and crank f porting the 4file shaftr, c y

5. VA -burr Y remoti/ing yapparatus comprising vaV clampingrmeansffor Aholdingv an article, a knife foncutting burrs ffromone portion ofthe article, av'vijlefor ling'burrs from another portion of the article, a cam and crank shaft rotatable through a single cycle to cause operation of the clamping means, the knife and the le, means mounted on the cam shaft for resiliently supporting the file with respect to the shaft, and a cam encircling the cam shaft for deecting the knife eccentrically of the shaft.

6. In a burr removing apparatus, a camming pin movable in a circular path,r a slidable and oscillatable lever driven by said pin, burr removing means carried by said lever, and means for guiding said lever in a straight line during part of the movement of the camming pin, said means being movable by the lever during another part of the movement of the pin to guide the lever during its movement in a substantially semicircular path.

7. In a burr removing. apparatus, a camming pin movable in a circular path, a slidable and oscillatable lever driven by said pin, burr remov- 10 ing means carried by said lever, camming surfaces formed on said lever for `engagexfnent by the pin, and means for guiding said lever in a straight line during part of the movement of the camming pin, said means being movable by the lever during another part of the movement of the pin to guide the lever during its movement in a semi-circular path.

8. In a burr removing apparatus, -a cammlng pin movable through a circular path, a slidable and oscillatable lever having camming surfaces for engagement by said pin, means for urging said lever to follow a predetermined straight path and compressible by said lever during a portion of its travel under the action of the pin to guide an end of the lever in a semi-circular path, and burr removing knives carried by said lever.

JOHN W. KING. GEORGE STUHLFAUTH. 

